Re: [PATCH i-g-t 2/2] tests/intel/xe_evict: Reduce the "large" bo size for threaded eviction

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Thu, 2024-06-27 at 06:34 +0000, Matthew Brost wrote:
> On Wed, Jun 26, 2024 at 02:38:33PM +0200, Thomas Hellström wrote:
> > When calculating the number of bos that simultaneously fits in
> > VRAM + system memory, account for eviction pipelining by
> > subtracting
> > one bo for ongoing pipelined evictions per thread.
> > 
> > With large bos this may lead to us not being able to use a working
> > set of 2 bos, which is the minimum, so reduce the large bo size for
> > threaded evictions, and instead increase the default number of bos.
> > 
> > Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> > ---
> >  tests/intel/xe_evict.c | 41 +++++++++++++++++++++++++-------------
> > ---
> >  1 file changed, 25 insertions(+), 16 deletions(-)
> > 
> > diff --git a/tests/intel/xe_evict.c b/tests/intel/xe_evict.c
> > index 5691ad021..13e90d317 100644
> > --- a/tests/intel/xe_evict.c
> > +++ b/tests/intel/xe_evict.c
> > @@ -484,10 +484,16 @@ static unsigned int working_set(uint64_t
> > vram_size, uint64_t system_size,
> >  	if (flags & MULTI_VM)
> >  		set_size *= 2;
> >  
> > -	/* All bos must fit in memory, assuming no swapping */
> > -	total_size = ((vram_size - 1) / bo_size + system_size /
> > bo_size) /
> > +	/*
> > +	 * All bos must fit in memory, assuming no swapping.
> > Subtract one bo per
> > +	 * thread for an active eviction.
> > +	 */
> > +	total_size = ((vram_size - 1) / bo_size + (system_size -
> > 1) / bo_size - 1) /
> 
> Had a comment in previous patch about 'system_size / bo_size' too.
> 
> Why change this to (system_size - 1) here?

It's to round down if the large bos is an exact multiple of system
size. However, with the comment on the previous patch I think it makes
more sense to use a fraction, say 90% of available system size. I'll
check if igt has a way of detecting available swap size as well...

/Thomas


> 
> I get the '- 1' at the end.
> 
> Matt
> 
> >  		num_threads;
> >  
> > +	igt_debug("num_threads: %d bo_size : %lu total_size : %lu
> > \n", num_threads,
> > +		  bo_size, total_size);
> > +
> >  	if (set_size > total_size)
> >  		set_size = total_size;
> >  
> > @@ -741,13 +747,13 @@ igt_main
> >  			MIXED_THREADS | THREADED },
> >  		{ "mixed-many-threads-small", 3, 16, 128, 1, 128,
> >  			THREADED },
> > -		{ "threads-large", 2, 2, 4, 3, 8,
> > +		{ "threads-large", 2, 2, 16, 3, 32,
> >  			THREADED },
> > -		{ "cm-threads-large", 2, 2, 4, 3, 8,
> > +		{ "cm-threads-large", 2, 2, 16, 3, 32,
> >  			COMPUTE_THREAD | THREADED },
> > -		{ "mixed-threads-large", 2, 2, 4, 3, 8,
> > +		{ "mixed-threads-large", 2, 2, 16, 3, 32,
> >  			MIXED_THREADS | THREADED },
> > -		{ "mixed-many-threads-large", 3, 2, 4, 3, 8,
> > +		{ "mixed-many-threads-large", 3, 2, 16, 3, 32,
> >  			THREADED },
> >  		{ "threads-small-multi-vm", 2, 16, 128, 1, 128,
> >  			MULTI_VM | THREADED },
> > @@ -755,11 +761,11 @@ igt_main
> >  			COMPUTE_THREAD | MULTI_VM | THREADED },
> >  		{ "mixed-threads-small-multi-vm", 2, 16, 128, 1,
> > 128,
> >  			MIXED_THREADS | MULTI_VM | THREADED },
> > -		{ "threads-large-multi-vm", 2, 2, 4, 3, 8,
> > +		{ "threads-large-multi-vm", 2, 2, 16, 3, 32,
> >  			MULTI_VM | THREADED },
> > -		{ "cm-threads-large-multi-vm", 2, 2, 4, 3, 8,
> > +		{ "cm-threads-large-multi-vm", 2, 2, 16, 3, 32,
> >  			COMPUTE_THREAD | MULTI_VM | THREADED },
> > -		{ "mixed-threads-large-multi-vm", 2, 2, 4, 3, 8,
> > +		{ "mixed-threads-large-multi-vm", 2, 2, 16, 3, 32,
> >  			MIXED_THREADS | MULTI_VM | THREADED },
> >  		{ "beng-threads-small", 2, 16, 128, 1, 128,
> >  			THREADED | BIND_EXEC_QUEUE },
> > @@ -769,13 +775,13 @@ igt_main
> >  			MIXED_THREADS | THREADED | BIND_EXEC_QUEUE
> > },
> >  		{ "beng-mixed-many-threads-small", 3, 16, 128, 1,
> > 128,
> >  			THREADED | BIND_EXEC_QUEUE },
> > -		{ "beng-threads-large", 2, 2, 4, 3, 8,
> > +		{ "beng-threads-large", 2, 2, 16, 3, 32,
> >  			THREADED | BIND_EXEC_QUEUE },
> > -		{ "beng-cm-threads-large", 2, 2, 4, 3, 8,
> > +		{ "beng-cm-threads-large", 2, 2, 16, 3, 32,
> >  			COMPUTE_THREAD | THREADED |
> > BIND_EXEC_QUEUE },
> > -		{ "beng-mixed-threads-large", 2, 2, 4, 3, 8,
> > +		{ "beng-mixed-threads-large", 2, 2, 16, 3, 32,
> >  			MIXED_THREADS | THREADED | BIND_EXEC_QUEUE
> > },
> > -		{ "beng-mixed-many-threads-large", 3, 2, 4, 3, 8,
> > +		{ "beng-mixed-many-threads-large", 3, 2, 16, 3,
> > 32,
> >  			THREADED | BIND_EXEC_QUEUE },
> >  		{ "beng-threads-small-multi-vm", 2, 16, 128, 1,
> > 128,
> >  			MULTI_VM | THREADED | BIND_EXEC_QUEUE },
> > @@ -783,11 +789,11 @@ igt_main
> >  			COMPUTE_THREAD | MULTI_VM | THREADED |
> > BIND_EXEC_QUEUE },
> >  		{ "beng-mixed-threads-small-multi-vm", 2, 16, 128,
> > 1, 128,
> >  			MIXED_THREADS | MULTI_VM | THREADED |
> > BIND_EXEC_QUEUE },
> > -		{ "beng-threads-large-multi-vm", 2, 2, 4, 3, 8,
> > +		{ "beng-threads-large-multi-vm", 2, 2, 16, 3, 32,
> >  			MULTI_VM | THREADED | BIND_EXEC_QUEUE },
> > -		{ "beng-cm-threads-large-multi-vm", 2, 2, 4, 3, 8,
> > +		{ "beng-cm-threads-large-multi-vm", 2, 2, 16, 3,
> > 32,
> >  			COMPUTE_THREAD | MULTI_VM | THREADED |
> > BIND_EXEC_QUEUE },
> > -		{ "beng-mixed-threads-large-multi-vm", 2, 2, 4, 3,
> > 8,
> > +		{ "beng-mixed-threads-large-multi-vm", 2, 2, 16,
> > 3, 32,
> >  			MIXED_THREADS | MULTI_VM | THREADED |
> > BIND_EXEC_QUEUE },
> >  		{ NULL },
> >  	};
> > @@ -823,6 +829,7 @@ igt_main
> >  					     1, s->flags);
> >  
> >  			igt_debug("Max working set %d n_execs
> > %d\n", ws, s->n_execs);
> > +			igt_skip_on_f(!ws, "System memory size is
> > too small.\n");
> >  			test_evict(fd, hwe, s->n_exec_queues,
> >  				   min(ws, s->n_execs), bo_size,
> >  				   s->flags, NULL);
> > @@ -836,6 +843,7 @@ igt_main
> >  					     1, s->flags);
> >  
> >  			igt_debug("Max working set %d n_execs
> > %d\n", ws, s->n_execs);
> > +			igt_skip_on_f(!ws, "System memory size is
> > too small.\n");
> >  			test_evict_cm(fd, hwe, s->n_exec_queues,
> >  				      min(ws, s->n_execs),
> > bo_size,
> >  				      s->flags, NULL);
> > @@ -849,6 +857,7 @@ igt_main
> >  					     s->n_threads, s-
> > >flags);
> >  
> >  			igt_debug("Max working set %d n_execs
> > %d\n", ws, s->n_execs);
> > +			igt_skip_on_f(!ws, "System memory size is
> > too small.\n");
> >  			threads(fd, hwe, s->n_threads, s-
> > >n_exec_queues,
> >  				min(ws, s->n_execs), bo_size, s-
> > >flags);
> >  		}
> > -- 
> > 2.44.0
> >